import java.util.HashMap;
import java.util.HashSet;
import java.util.LinkedHashMap;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;

public class HashMapSourceTest {
    public static void main(String[] args) {
//        System.out.println("准备初始化map对象");
//        HashMap<String,Object> map = new HashMap<>();
//        System.out.println("准备添加数据！");
//        map.put("zhangsan", 15);
//        map.put("lisi", 20);
//
        ConcurrentHashMap<String,Object> cmap = new ConcurrentHashMap<>();
        cmap.put("wangwu", 25);
        HashMap<String,Object> map = new HashMap<>();
        map.put("a", 1);
        map.get("a");
        HashSet<String> set = new HashSet();
        set.add("aa");
        LinkedHashMap<String,Object> lmap = new LinkedHashMap<>();
        lmap.put("vv",12);
    }
}
